The invention relates to a subsea equipment used for natural gas or crude oil production, such as subsea actuators for a valves, restrictors or the like, control modules, so-called BOP (blowout preventors), or other means, and comprising at least one closed, oil-filled first component and a first compensator unit which is associated with said first component and which is in fluid communication therewith for pressure compensation,
Such subsea equipment is arranged in situ on the seabed, on a so-called tree, on an oil platform and other components for natural gas or crude oil production. A subsea actuator serves e.g. to adjust a valve or a restrictor so as to interrupt, or at least vary the flow through respective pipes. Also for the so-called blowout preventor, an actuator is used. Such a blowout preventor serves to prevent, in emergency cases, crude oil or natural gas from escaping on the seabed from respective pipes at the well.
In the case of a closed, oil-filled subsea equipment, a respective component has normally associated therewith a compensator unit for pressure compensation. Pressure compensation is effected between the component and the environment, i.e. the water. The pressure compensated is the hydrostatic pressure (water depth) and also pressure differences caused by changes in temperature and/or volume. One example for a change in volume is here e.g. a piston which is movable in a cylinder.
In subsea equipments known in practice, a component or a plurality of components has associated therewith a respective compensator unit which accomplishes pressure compensation separately for the component associated therewith. If the compensator unit in question fails to operate due to the occurrence of a leak or the like, the function of the associated component will at least be impaired or the component will perhaps no longer be capable of functioning at all.
It is therefore the object of the present invention to improve a subsea equipment of the type referred to at the beginning in a structurally simple manner in such a way that it is still capable of functioning and that pressure compensation is still possible, even if the associated compensator unit is damaged or fails to operate. In connection with the features of the generic clause of claim 1, this object is achieved in that a second compensator unit is in fluid communication with the first component or the first compensator unit for pressure compensation.